Export of internal Abseil changes

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53550735f5a943dfb99225e7c53f211c2d6e7951 by Gennadiy Rozental <rogeeff@google.com>:

Import of CCTZ from GitHub.

PiperOrigin-RevId: 309333648

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847bbf8a1d9cd322ec058c6f932d1f687fd3d331 by Gennadiy Rozental <rogeeff@google.com>:

Make Validation interfaces private in CommandLineFlag.

Calls are rewired via private interface access struct.

PiperOrigin-RevId: 309323013

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a600fc5051e0a0af50a7850450fd3ed1aef3f316 by Matthew Brown <matthewbr@google.com>:

Internal Change.

PiperOrigin-RevId: 309292207

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937d00ce3cf62c5f23f59b5377471fd01d6bfbc7 by Gennadiy Rozental <rogeeff@google.com>:

Make TypeId interface private in CommandLineFlag.

We also rewire the SaveState via the new PrivateHandleInterface trampoline class. This class will be the only way to access private methods of class CommandLineFlag.

PiperOrigin-RevId: 309282547

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796c4bd35073b6a8337762bdb13603dae12a4df1 by Derek Mauro <dmauro@google.com>:

Cleanup uses of kLinkerInitialized

PiperOrigin-RevId: 309274734

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c831446c52d9ef4bdcb1ea369840904620abc4b9 by Gennadiy Rozental <rogeeff@google.com>:

Eliminate the interface IsModified of CommndLineFlag.

PiperOrigin-RevId: 309256248

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a1db59d7f7aa39cb0a37dbf80f8c04e371da8465 by Gennadiy Rozental <rogeeff@google.com>:

Avoid default value generator if default value expression is constexpr.

If possible, we detect constexpr-ness of default value expression and avoid storing default value generator in side of flag and instead set the flag's value to the value of that expression at const initialization time of flag objects.

At the moment we only do this for flags of (all) integral, float and double value types

PiperOrigin-RevId: 309110630

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ae3b4a139aacd8fc165c9acd2a3cbae1f9e26af4 by Gennadiy Rozental <rogeeff@google.com>:

Make SaveState a private method of the CommandLineFlag and make it only accessible from FlagSaverImpl. There is no other call sites for this call.

PiperOrigin-RevId: 309073989

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cbc24b4dcc166dd6b0208e9d7620484eaaaa7ee0 by Abseil Team <absl-team@google.com>:

Eliminate the interface IsModified of CommndLineFlag.

PiperOrigin-RevId: 309064639

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08e79645a89d71785c5381cea9c413357db9824a by Gennadiy Rozental <rogeeff@google.com>:

Eliminate the interface IsModified of CommndLineFlag.

PiperOrigin-RevId: 309054430

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4a6c70233c60dc8c39b7fa9beb5fa687c215261f by Gennadiy Rozental <rogeeff@google.com>:

Internal change

PiperOrigin-RevId: 308900784

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13160efdf7710f142778d5a1e4c85aa309f019b6 by Abseil Team <absl-team@google.com>:

Provide definitions of static member variables -- improved C++11 support.

PiperOrigin-RevId: 308900290

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0343b8228657b9b313afdfe88c4a7b2137d56db4 by Gennadiy Rozental <rogeeff@google.com>:

Rename method Get<T> to TryGet<T> per approved spec before making interface public.

PiperOrigin-RevId: 308889113

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7b84e27fb857fc1296a05504970f506d47d2f2c1 by Derek Mauro <dmauro@google.com>:

Remove node_hash_* methods that were deprecated on release

PiperOrigin-RevId: 308837933

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599d44ee72c02b6bb6e1c1a1db72873841441416 by Gennadiy Rozental <rogeeff@google.com>:

Eliminate CommandLineFlag::Typename interface per approved spec before making CommandLineFlag public.

PiperOrigin-RevId: 308814376
GitOrigin-RevId: 53550735f5a943dfb99225e7c53f211c2d6e7951
Change-Id: Iae52c65b7322152c7e58f222d60eb5a21699a2cb

1 files changed, 30 insertions, 16 deletions

diff --git a/absl/flags/internal/commandlineflag.h b/absl/flags/internal/commandlineflag.h
index ef992f7f..f807fb9a 100644
--- a/absl/flags/internal/commandlineflag.h
+++ b/absl/flags/internal/commandlineflag.h
@@ -93,7 +93,7 @@ class CommandLineFlag {
   // Attempts to retrieve the flag value. Returns value on success,
   // absl::nullopt otherwise.
   template <typename T>
-  absl::optional<T> Get() const {
+  absl::optional<T> TryGet() const {
     if (IsRetired() || !IsOfType<T>()) {
       return absl::nullopt;
     }
@@ -130,29 +130,14 @@ class CommandLineFlag {
   virtual absl::string_view Name() const = 0;
   // Returns name of the file where this flag is defined.
   virtual std::string Filename() const = 0;
-  // Returns name of the flag's value type for some built-in types or empty
-  // string.
-  virtual absl::string_view Typename() const = 0;
   // Returns help message associated with this flag.
   virtual std::string Help() const = 0;
   // Returns true iff this object corresponds to retired flag.
   virtual bool IsRetired() const;
-  // Returns true iff this is a handle to an Abseil Flag.
-  virtual bool IsAbseilFlag() const;
-  // Returns id of the flag's value type.
-  virtual FlagFastTypeId TypeId() const = 0;
-  virtual bool IsModified() const = 0;
   virtual bool IsSpecifiedOnCommandLine() const = 0;
   virtual std::string DefaultValue() const = 0;
   virtual std::string CurrentValue() const = 0;
 
-  // Interfaces to operate on validators.
-  virtual bool ValidateInputValue(absl::string_view value) const = 0;
-
-  // Interface to save flag to some persistent state. Returns current flag state
-  // or nullptr if flag does not support saving and restoring a state.
-  virtual std::unique_ptr<FlagStateInterface> SaveState() = 0;
-
   // Sets the value of the flag based on specified string `value`. If the flag
   // was successfully set to new value, it returns true. Otherwise, sets `error`
   // to indicate the error, leaves the flag unchanged, and returns false. There
@@ -174,9 +159,38 @@ class CommandLineFlag {
   ~CommandLineFlag() = default;
 
  private:
+  friend class PrivateHandleInterface;
+
+  // Returns id of the flag's value type.
+  virtual FlagFastTypeId TypeId() const = 0;
+
+  // Interface to save flag to some persistent state. Returns current flag state
+  // or nullptr if flag does not support saving and restoring a state.
+  virtual std::unique_ptr<FlagStateInterface> SaveState() = 0;
+
   // Copy-construct a new value of the flag's type in a memory referenced by
   // the dst based on the current flag's value.
   virtual void Read(void* dst) const = 0;
+
+  // Interfaces to operate on validators.
+  // Validates supplied value usign validator or parseflag routine
+  virtual bool ValidateInputValue(absl::string_view value) const = 0;
+};
+
+// This class serves as a trampoline to access private methods of
+// CommandLineFlag. This class is intended for use exclusively internally inside
+// of the Abseil Flags implementation
+class PrivateHandleInterface {
+ public:
+  // Access to CommandLineFlag::TypeId.
+  static FlagFastTypeId TypeId(const CommandLineFlag& flag);
+
+  // Access to CommandLineFlag::SaveState.
+  static std::unique_ptr<FlagStateInterface> SaveState(CommandLineFlag* flag);
+
+  // Access to CommandLineFlag::ValidateInputValue.
+  static bool ValidateInputValue(const CommandLineFlag& flag,
+                                 absl::string_view value);
 };
 
 // This macro is the "source of truth" for the list of supported flag built-in